<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <script src="jquery-3.1.0.min.js"></script>
</head>
<body>
    <p id="p1">hello world</p>
    <button id="btn1">按钮</button>
    <p id="p2">hello world</p>
    <button id="btn2">按钮</button>
    <br/>
    <input type="text" id="i3" value="hello world"/>
    <button id="btn3">按钮</button>
    <br/>
    <a href="http:www.baidu.com" id="id4">最初是百度，接下来是jikexueyuan</a>
    <button id="btn4">按钮</button>

    <script>
        $(document).ready(function(){
            $("#btn1").click(function(){
                $("#p1").text("jikexueyuan") //hello world 修改成jikexueyuan，内容的修改
            });
            $("#btn2").click(function(){
                $("#p2").html("<a>jikexueyuan</a>") //标签的修改
            });
            $("#btn3").click(function(){
                $("#i3").val("jikexueyuan")
            });
            $("#btn4").click(function(){
                $("#id4").attr("href","http://www.jikexueyuan.com") //标签的修改
            });
        })
    </script>
</body>
</html>